Train control



Julyy 14,l 1931.

C. S. WILLIAMS VTRAIN lCONTROL Filed Aug. 5l, 1928 A f Ll uf T /f mw.;V3I m8 E f, M HY/ CB ATTORNEY .amm 2.255@

Patented July 14, 1931 @mams s. WILLIAMS, or Kllsfnolt, Y1e

TRAIN ooNmItQL @vocation me@ @tout 314.22%-, .Ssrtawo- 303,124-

.Y employing oo tho ,Souroo ot ti" @j f track is divided into a seriesof blocks including the home or occupied block 11, the caution blocks 12and 13 and the clear blocks 14 and 14. ln the following description itwill be understood that the locomotive 15 is traveling in the directionof the arrow, that is, from right to left. Paralleling the track 10 isthe transmission line 16 from which alternating current is supplied tothe exit ends of each of the blocks 12, 13, 14 and 14 through thecircuits 17, 18, 19 and 19, each of which latter circuits includes aline transformer, a. track transformer, and a battery connected inseries with the secondary of the track transformer. Connected across thetracks o-f each block at the entrance end thereof is a direct currenttrack relay, it being noted that this track relay for any particularblock is connected in series with the secondary of the track transformerfor that block. lt will thus be evident that each block is a conipletecircuit in itself to which both alternating and direct current issupplied, the former being supplied from the 'transmission line 16 andthe latter from the battery.

As clearly appears in Figure 1, the signal 24a for the blo-ck 11indicates danger or an occupied block, this because of the fact that thelocomotive 15 has shunted the rails of this block .thereby preventingany alternating or direct current from flowing between the rear end ofthe locomotive and the signal 24a. In consequence of this, the trackrelay 23a for the occupied block 11 has become deenergized and so haspermitted the contact lingers (designated generally by the numeral a) todrop into the position shown in Diagram A of Figure 1. inasmuch as boththe upper and lower quadrants of the signal 24a are controlled by thesecontact fingers, the dropping of the latter causes both arms of thesignal to assume the upright position indicating danger or an occupiedblock.

Simultaneously as the track relay 23a is deenergized, the relay 26 isalso deenergized (due to the opening of the lowermost contact 25a),thereby opening, as at 23, the circuit of the secondary of the linetransformer 20a. The alternating current supply to the block 12, throughthe circuit 17, is thus interrupted. This blo-ck 12 is, however,supplied with direct current from the battery source 22a, which latteris connected in series with the secondary of the track transformer 21a.This direct current is sutiicient to energize the track relay 236connected across the rails of block 12, with the result that the contactfingers 256 (see Diagram B) are raised into the position shown. Thiscompletes the circuit to the operating mechanism for the upper quadrantof the caution signal 246 for block 12, causing the corresponding arm tobe held at an angle. Tnasmuch as the operating circuits for therespective signals are of the usual character and do not form anessential part of the present invention, they have not been described indetail herein.

Movement of the upper arm of signal 246 into the inclined positioncauses its associated contactarme to shift from the vertical positionsshown in Diagram A to the inclined positions shown in Diagram B, therebycompleting the energizing circuit for the relay 32. This relay 32 isenergized by the battery 606 of Diagram B, the circuit therefor beingtraced as follows z-from lower terminal of battery 606 through wires 61,62, 63, relay 32 and wire 64 to the upper terminal of battery 606. Dueto the fact that the relay 26 remains deenergized, the relay 29 isdeenergized with the result that the lower quadrant of signal 246remains in upright position. The signal 246 thus indicates caution forthe block 12.

Deenergization of the relay 30 opens, as at 31, the circuit of thesecondary of the line transformer 206 with the result that thealternating current supply to the block 13 is interrupted. This bloc-k13 is, however, sup plied with direct current from the battery source226, which latter i-s connected in series with the secondary of thetrack transformer 216. This direct current is suiicient to energize thetrack relay 230 connected across the rails of block 13, with the resultthat the contact lingers 250 (see Diagram C) are raised into theposition shown. This completes the circuit to the operatingmechanism forthe upper quadrant of the caution signal 240 for block 13, causing thecorresponding arm to be held at an angle. The lower quadrant remainsinthe upright position, however, this being due to the fact that relay34 remains deenergized so long as the contacts 276 are open through thedeenergization of the relay 30, the latter being in circuit with thebattery a of Diagram A. The current for energizing the relay 34 isderived from the battery 606.

Energization of the track relay 230 for block 13 also elfects theclosing of the lowermost contact 25a (see Diagram C), thereby7 causingthe relay 32 to become energized. Energization of the relay 32 effectsthe closing, as at 33, of the secondary circuit of the line transformer20c, thereby sending alternating current through the rails of block 14by way of the circuit 19. lt will be noted that, as in the case of block13, the direct current track relay 2366 for block 14 is energized fromthe battery 220 connected in series with the secondary of tracktransformer 210 at the eXit end of block 14. (See Diagram C.) Due to theclosing of contacts 27d through the energization of the last mentionedtrack relay 23d, the relay 32 is energized, thereby causing the contacts33 to close. The relay 32 is in circuit with the battery 600 of DiagramC. Alternating current is then supplied to the rails of block 14 taler?thmug'h, the circuit. design/@Qd by the M nleral 19.' (SlewefD'agm D1).s i.

' clined in this manner the indication is that the block ahead is clearof all traiic.A

With the blocks ll, 12, 18 and 14 maintaining the prevailing conditionsshown in Figure l, and assuming the entrance of a train into block 14,the signal in the locomotive cab should remain green or clear and itshould be possible for the train to run at any desired speed until itreaches the first caution block 13'. Immediately upon entering thiscaution block, the cab indication should change from green or clear toyellow or caution, this change in the cab signal being effected byreason of the fact that there is no alternating current flowing in thecaution block. It will be remembered, as explained hereinbefore, thatthe alternating current supply is opened to all but the clear blocks.

Referring now to Figure 2 showing a typical locomotive circuit for usein connection with the Wayside circuit briefly described hereinbefore,it Will be observed that the energy for the dynamotor 35 is furnished bythe locomotive headlight generator, designated generally by the numeral36. The dynamotor 35 is employed for supplying energy to the platecircuit of the amplifier 37, the energy for the amplifier tube lilamentsbeing supplied by the generator 36. Suitably carried by the locomotiveis .a receiver 38 comprising the pick-up coils 39 and the laminatedsteel bar 40 grounded to the locomotive. coils form, in effect, acapacitive condenser through which the latter are grounded to thelocomotive.

The receiver Vcoils are suitably connected to the input side of theamplifier 37 so that when alternating current is iiowing in the railsand a voltage is induced in the receiver coils above them, alternatingcurrent is caused to flow through the primary of the output transformer4l. In usual practice, it is customary to enclose the wires leading fromthe receiver to the amplifier in a conduit 42 which is grounded to thelocomotive, thereby creating a capacitive coupling through which theconduit-enclosed Wires ae grounded.

The alternating current delivered by the transformer 41 in response toenergization of The bar 40 and the picleup the track receiveris'rectilied by a static rectiiierltttd .lillfllet FETT-.entitlllll-Sblial is enpioye' tu energize uref aire-@tremare control`relay`44- Assuming thelo'c'@ motive. to be traveling in unrestrictedterritry5'tl1at-isljna ,leaf bluckg'the altern l: J 'lion/'ing 'in'therailsthereffvvi y picked up bythe receiverSSfor energZft'-tionuoffthetrain control relay 44.y Wheirthe latter'is so'en'ergizred,the contacts 45 lare raised tothe position shown in Figure'Q, withMaremma energy Supplied ,from the' generator B6' tothe green or'clea'rsignal 4Ginthe"locomotive'cabl lll-l-zfi the in .enters a restrictedblock, r

either caution orl occupied, the Vrelay'4/4 'e'nerg "due vto vthe i factthat there is no alternating current'llowing inr the rails of are,restricta@ bleek, wat uw resta, aait-he contacts ylkdro'p vinto thedotted p'Q-Sition. Entrer iS then .Supplied from the tilftf toit-lieyellovvv or caution signal'4 and to thesignal bell 48, notifyllgtheengniiltn that hef is in restricted'or,dangerous teV tfry' The fqrgng'descrlieSj-thefoii ation ofthe, locomotive circuit with all of `he.annilrtenant' iPara-tus 'functioning ardu'- erlyr.

Let us assume, however, that one of the armature coils becomes grounded,as'at'49 in '2. alternatingmcurrent is immediyeuesf-abhshed which flowses indicted by from the grounded armatu'recoil to the grounded'conduit'42 or the" grounded rciver 3S? 'Thisv Siliitfmpastd alternatingCiirrentupaSSQ/S, through the' primary of Ythe ti"'anrrner,` 41." lAnalternating Current 'is tli'us',y deiveredbythe transformer Awhich isfit'd b5 .tldrletier 43far'netgzat01 @Tr-niej train entroi relay" n. Theresulta-S ,thatthe contactsi'45 areraised to the full line positionshov'vn Figure Q' Withv the conse'- .tiiienaethae, ,i

46d'isi bi'faiiie'ol.`A It Will beobserved tlflatthis indica-tion is,obtained independently' '0f any voltage' 'induced in 4the receiver'3,8' and irre- -spectiveof Whether `or not alternating cur- MSiflQWing'in thefrails. Gbviously, the train'con'trol relay 44 shouldlnever be ener# gizfedfverrceptbythe'ivoltage induced iIi ,rec:eiverythe vlo `zomotive travels over a `,block` inthe rails ofivhichkallternating curf ientisffloivving As has beenexplained hereinbefore,there isnoalternating current flow inthe'caution or occupied blocks.

. To'ayoidtheabovedescribed possibility of a reen or clear lightindica-'tionV vico geo

ythere has been shown one form of motor for sleeve or bushing 54. Theends of the coil mounting are covered by insulating disks 55 and thoseof the c-ommutator by the insulating disks 5G. The use of a generatorembodying an insulated armature unit constructed along the lines shownin Figure 3 effectually precludes the possibility of grounding of one ormore of the current generating coils through the housing or othermetallic parts .of the generator and thereby prevents the generation ofthat superimposed alternating current which operates to create a falseclear condition when the train is traveling in caution or occupiedblocks. y

Although the present invention has been described in connection with arather specific system'of automatic train control, it will beunderstood, of course, that the present invention is applicable to manyother train control systems, and, therefore, should not be limited inscope to the particular system shown eX- cept as indicated by theappended claims.

llVhat is claimed as new and useful is:

l. In an automatic train control locomotive circuit, in combination, adirect current generator, an amplifier circuit having an outputtransformer, an alternating current receiver included in said amplifiercircuit for energizing the primary of said transformer, said receiverbeing grounded through a capacitive condenser, and means for insulatingthe armature of said generator against the grounding of one or more ofthe current generating coils thereof whereby to eifectually preclude thegeneration of an alternating current which flows between said groundedcoil and said grounded receiver through the primary of said transformer.

2. In the locomotive circuit of an automatic train control system, incombination, an amplilier circuit including an output transformer, atrain control relay energizable from the secondary of said transformer,an alternating current pick-up coil included ink said amplifier circuitfor energizing the primary of said transformer, said pick-up coil beinggrounded, and a generator for supplying energy to the amplifier, thearmature of said generator being insulated against the grounding of oneor more of the current generating coils thereof whereby to prevent thepassage of alternating current from a grounded current generating coilto the grounded pick-up coil through the primary of said transformer andthus obtain an undesired energization of said train control relay.

3. In an automatic train signal circuit, in combination, a directcurrent generator, an amplifier circuit the output of which is connectedto a relay controlling the operation of CHARLES S. VILLIAMS.

